As noted, Nagel wants to preserve some version of naturalism because he is averse to theism (or at least theism in certain versions, to judge from Mind and Cosmos). His doubts about the comprehensive explanatory adequacy of neo-Darwinian evolutionary theory, insistence on the irreducibility of consciousness and rationality to material explanations, and rejection of metaphysical materialism shocked his colleagues – all of them, like everyone in research universities, members of an academic culture in which materialist, reductionist naturalism is a largely unquestioned and uncritically accepted default assumption.
But naturalism has a bigger, even more fundamental problem than the mystery of consciousness, first-person experience, intentionality, and rationality, and that is, quite simply, the fact of existence, period – that there is anything whatsoever, none of which accounts for or can account for its own existence. Significantly, Nagel nowhere raises this issue in Mind and Cosmos, although he draws close when he states that «[t]he world is an astonishing place, and the idea that we have in our possession the basic tools needed to understand it is no more credible now than it was in Aristotle’s day.» Clearly, he is not talking about scientific explanation when he says of the world «[t]hat it has produced you, and me, and the rest of us is the most astonishing thing about it» (7). Especially astonishing to him is the fact that conscious, rational beings have evolved, which leads him to advocate for a teleological, non-materialist naturalism. Yet properly grasped, the radical contingency of everything that exists and that the natural sciences investigate or could investigate is a logical and metaphysical death knell for naturalism at a more fundamental level. It is part of expanded reason’s revenge on the unjustified restriction of reason to the epistemological imperialism of scientism. And this recognition is itself the product of the exercise of reason – a faculty capable of distinguishing between empirical and conceptual questions, and of understanding that nothing whatsoever in nature, nor nature as a whole, can explain its own existence.
There are plenty of physicists who understand this, and realize that their discipline can study only physical processes and natural laws, not how or why there are any physical processes or natural laws whatsoever. But metaphysical naturalists who believe in physics as first philosophy are oblivious of this distinction. Some think, for example, that if we can explain everything back to the instant of the Big Bang itself, to the most basic, primordial conditions that were followed by the expansion of the universe with such incomprehensible power and accelerating velocity, we would have explained the mystery of existence. An entirely physical, naturalist cosmology would be tantamount to a comprehensive ontology. But this is fundamentally confused, and ultimately irrational: it fails to recognize that whatever were the most elementary conditions and character of natural reality at the moment of the Big Bang, they are ontologically no less contingent – no more capable of explaining the fact of their existence – than is our universe in its ever-expanding, highly differentiated form 13.7 billion years later. To see this is to realize the rational inference that follows: something ontologically beyond or outside the entire natural order that is not contingent must exist, something which can and does both in principle and in fact account for the existence of the natural order – even though how this is so remains not merely obscure, but vertiginously incomprehensible. On the other hand, to insist that there must be something ontologically contingent that is «just there,» that «the natural order» or «natural laws» or «nature as such» or «the basic physical constituent realities of the universe» are somehow simply a given and whose existence need not be explained, is nothing less than the abdication of reason at the analytical endpoint of precisely the rational process that seeks to understand the totality of human experience, human history, the natural history of our world, and the history of the universe, by showing the interconnected, integral character of different sorts of knowledge gained through all the academic disciplines. It is irrationally to draw back from the precipice of reason to which reason itself leads. Positing any brute facticity of existence to the universe, nature, natural laws, matter-energy, or the like amounts to physics refusing to yield to philosophy not simply when it «should,» but must, and this according to its own principles – provided those principles are well understood. A failure to do so indicates a failure to understand what science itself can and cannot do, what the natural sciences are in contrast to what they cannot be; it is symptomatic of the unwarranted metastasis of naturalism into a metaphysical assertion. The crucial distinction in question can be helpfully brought out by comparing the relevant arguments from two books published in the last decade: A Universe from Nothing: Why There Is Something Rather Than Nothing (2012), by the American cosmologist Lawrence Krauss; and The Experience of God: Being, Consciousness, Bliss (2013), by the American philosopher and theologian David Bentley Hart.
Like other scientists who write well for a general audience, Krauss can be engaging when he is discussing the extraordinary discoveries in cosmology and the remarkable features of our universe as disclosed since the early twentieth century. But when he endeavors to make good on the claim in his book’s title and subtitle, he quickly shows that he either cannot or does not want to consider escape from the self-imposed prison of restricted reason that he inhabits. The results are unfortunate. An alert reader is bound to be puzzled already in the Table of Contents with chapter titles that include «Nothing is Something» and «Nothing is Unstable,» and in the preface, one can see that treatment of the central issue at hand is unlikely to go well.16 Oblivious of the basic conceptual difference between contingent and necessary being, or between a first efficient cause and a ground that makes any efficient causal order possible, Krauss asks blithely, «what is the difference between arguing in favor of an eternally existing creator versus an eternally existing universe without one?» (xii) He asserts that the question, «Why is there something rather than nothing?» «is usually framed as a philosophical or religious question» – which is descriptively correct – but then mistakenly adds that «it is first and foremost a question about the natural world, and so the appropriate place to try and resolve it, first and foremost, is with science» (xiii). With unwitting incomprehension, Krauss states that his book’s purpose is to «show how modern science, in various guises, can address and is addressing the question of why there is something rather than nothing,» and that both experiments and theories in modern physics «all suggest that getting something from nothing is not a problem. Indeed, something from nothing may have been required for the universe to come into being» (xiii). Conceding that «we may never have enough empirical information to resolve this question unambiguously» – unaware that no amount could ever be enough – he demonstrates from within the confines of his constricted, naturalist worldview that he does not even grasp what is at issue: «For surely ‘nothing’ is every bit as physical as ‘something,’ especially if it is to be defined as the ‘absence of something’» (xiii, xiv). The philosophers and theologians, he opines, have been «focusing on questions of nothingness without providing any definition of the term based on empirical evidence» (xvi). These are all exact, direct quotations.
With prefatory statements such as these, it is not surprising that nowhere in Krauss’s book – which again, is interesting and informative when treating twentieth-century cosmology – does he even engage the question he ostensibly seeks to answer. He seems unaware that the empirical and theoretical questions of physics on which he focuses are different from «the possible question... of what, if anything, fixed the rules that governed such creation»